OCCURRENSE

Since the group 2A elements are relatively active metals, they occur in nature.

Beryllium, (Be) occurs in trace amount in nature. The most important ore of beryllium is beryl,(Be3Al2(Sio3)6

Magnesium, (Mg)- the principal useful ores of magnesium are dolomite, carnallite and epsom salt which is found in mineral water.

Calcium, (Ca)-compounds are widely distributed in nature, occurring as limestone or marble, gypsum and fluorite. They are also found in the earth’s crust.

The main component of

cement is CaO.

USES

Metallic beryllium is used to prepare some special -alloys. About 2% beryllium in copper produces a hard alloy especially suited for use in springs. The metal is used in making glass for X-ray tubes, so x-rays readily penetrate elements with low atomic number. Beryllium has the mechanical properties of a very light element.

Since magnesium is a light metal, it is used in the production of planes, missiles and some light household items. In alloys, it is used to increase the hardness, durability and resistance to corrosion. The light produced by the burning of magnesium tape with oxygen, is used as a flash in photography. Mg is also used as an additive in rocket fuels and signal rockets. Mg(OH)2, milk of magnesia is used as a stomach antacid.

The compounds of calcium, hydroxides, carbonates and oxides, are widely used as construction materials and as bleaching agents. Calcium oxide is the main compound in the production of some chemicals, steel, glass, paper and sugar. Calcium carbide (CaC2) is used to produce acetylene gas for welding.

Strontium has many important applications in industry. The salts of strontium are used in signal rockets and fireworks to produce red light.

Barium is used as a gas absorbent in vacuum tubes. Since the alloys of barium with nickel donate electrons by heating they are used in vacuum tubes and in ignitors. Barium nitrate (Ba(N03)2) and barium chlorate (Ba(N03)2) are used to obtain green light in fireworks. BaS04 (barium meal) is used to take the photos of stomach and intestines because, like all elements with large atomic number, it does not allow X-rays to pass. In fact, the Ba2+ ion is rather toxic, but since the solubility of BaS04 in water is very low, its poisonous effect disappears. Radium is used in selfluminous paints and in radiotherapy and as a neutron source

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